This invention relates in general to coupling devices, and more particularly to a quick-connect and disconnect coupling for conduits and the like.
Detachable connections for conduits and the like have conventionally comprised a pair of complementary threaded male and female members which were permanently mounted on the respective conduit ends. When connection of such a coupling was desired, the members were brought into contact and one member was rotated while the other member was kept stationary until rotation was impossible, so as to provide the threaded connection. Disconnection of the coupling involved a reversal of the above rotation. This type of coupling provided a satisfactory, leak-proof connection between conduits but was time consuming and could, in some cases, prove to be inconvenient.
Several coupling designs have been proposed in the prior art to simplify the connection and disconnection of conduits. One such design is disclosed in U.S. Pat. No. 3,635,501, to Thorne-Thomsen. The disclosed device comprises a female coupling which houses a snap ring possessing internally directed threaded lobes which engage and hold an inserted threaded male member. The operation of the device requires, however, the movement of an outer sleeve or cam-ring into contact with the snap ring to lock the male member in place after its insertion. Likewise, then, the reverse motion of the cam-ring is required to release the male member and permit its removal.
Another quick-connect design has been generally employed which provides the one-step connection of male and female coupling members and relies on the achievement of a locking engagement by entry of the two members into a predetermined position. Thus, for example, U.S. Pat. No. 3,352,576, to Thorne-Thomsen, provides a coupling assembly employing unthreaded male and female members wherein a locking means movably mounted in the female member engages an annular groove located on the male member. Upon insertion of the male member, a spring loaded sleeve mounted on the female member permits the expansion of the locking means and enables the male member to be inserted. Upon reaching the position within the female member whereby the locking means and the annular groove are in alignment, the locking means contracts into the annular groove and permits the sleeve to return to a position which holds the locking means in fixed engagement. Removal of the male member is accomplished by pulling back on the sleeve so as to permit the expansion of the locking means and the disengagement of the male member.
A variation of the one-step coupling is disclosed in U.S. Pat. No. 1,509,651, to Iftiger. Patentee's coupling likewise relies on the locking engagement of two unthreaded surfaces in a particular position, as tapered jaws are provided on a female member to engage an annular indentation on a nipple-like male member upon its full insertion. Release is accomplished by pulling back on an outer sleeve mounted on the female member, causing an attached inner sleeve to communicate with the tapered surfaces of the jaws and force them radially outward and away from contact with the annular groove.
As noted above, all of the previously mentioned coupling designs possess certain structural disadvantages. In the instance where the female coupling is adapted for use with a conventional threaded male coupling, the insertion of the male member into locking engagement requires the movement of a portion of the female coupling member, while those designs which afford one-step locking engagement require a connection between specially prepared unthreaded male and female coupling members which can only achieve locking engagement when united in one position.
In my above referenced parent application, a quick-connect coupling is disclosed which obviates the aforenoted prior art difficulties. A female coupling is provided for use with conventional threaded male couplings which employs as a novel locking means an inwardly sprung resilient snap ring. The snap ring is provided with internal threads for engaging the inserted male member in position and longitudinally projecting extensions which communicate with the angled end portion of an outer sleeve member when said member is pulled back, to force the radial expansion of the snap ring and the release of the male member.
Though the above coupling constitutes a marked advance over the prior art, it would be desirable to develop a coupling possessing greater adjustability with fewer moving parts which could be manufactured at a reduced cost.